Occurrence and genotypic identification of Blastocystis sp., Enterocytozoon bieneusi, and Giardia duodenalis in dairy cattle in Heilongjiang Province, China.

Blastocystis sp., Enterocytozoon bieneusi, and Giardia duodenalis are three common zoonotic intestinal parasites, and cattle are important hosts of these three intestinal protozoa. In this study, 1632 fecal samples were collected from dairy farms in Heilongjiang Province, China, and screened for Blastocystis sp., E. bieneusi, and G. duodenalis using polymerase chain reaction. Of these, 149 (9.13%) were positive for three zoonotic pathogens, including 104 (6.40%), 22 (1.35%), and 23 (1.41%) for Blastocystis sp., E. bieneusi, and G. duodenalis, respectively. Based on partial SSU rRNA gene sequencing analysis, 104 positive samples of Blastocystis sp. were found, and a total of nine known subtypes were identified, including ST10 (61), ST3 (18), ST14 (6), ST26 (7), ST24 (3), ST25 (2), ST1 (2), ST5 (2), and ST21 (1). Among these, three subtypes (ST1, ST3, and ST5) were recognized as zoonotic subtypes, and two subtypes (ST10 and ST14) were specific to animals. All 23 Giardia duodenalis-positive samples belonged to assemblage E (n = 23) based on sequenced beta-giardin (bg) and triosephosphate isomerase (tpi) genes. Three known genotypes of E. bieneusi, namely J (n = 9), I (n = 6), and BEB4 (n = 7), were identified by sequence analysis of the internal transcriptional spacer region gene. Our study provides basic data for prevention and control in Heilongjiang Province; however, further research is required to better understand the prevalence and public health significance of these pathogens in the Heilongjiang region.

Insight into the invasion process and immune-protective evaluation of Tp0971, a membrane lipoprotein from Treponema pallidum.

IMPORTANCE: The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum (T. pallidum) subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for early dissemination and immune evasion has earned it the designation "the stealth pathogen." There are many hurdles to studying syphilis pathogenesis, most notably the difficulty of culturing and genetically manipulating T. pallidum, as well as the absence of an effective vaccine for T. pallidum prevention. T. pallidum infection in humans is a complex and lengthy process. In this study, we investigated the invasion process and the function of the infection-dependent antigen Tp0971 as an immunogen to inhibit the dissemination of T. pallidum in an animal infection model. This enables a better understanding of the specific pathogenic mechanism of this pathogen, syphilis pathogenesis, and vaccine research.

Research status and perspectives for pathogenic spirochete vaccines.

Leptospira interrogans, Borrelia burgdorferi, and Treponema pallidum are important pathogenic spirochetes. The incidence of human diseases caused by pathogenic spirochetes, e.g., leptospirosis, Lyme disease, and syphilis, has been recently increased, posing a threat to public health. Mechanisms of spirochete pathogenicity are not yet fully understood, and no safe and effective vaccine to prevent and control the infection by pathogenic spirochetes is currently available. In this article, we review the progress of research into the pathogenic spirochete vaccine, mainly in terms of vaccine types. The development of relevant vaccines against pathogenic spirochetes has generally proceeded via several stages, such as the whole-cell inactivated vaccine, live attenuated vaccine, and gene-engineered vaccine, and will likely enter a new stage with the application of gene editing technology. In this review, we mainly summarized the types of pathogenic spirochete vaccines and conducted a preliminary analysis on the protective effect of immunity, and proposed a further prospect for the development of pathogenic spirochete vaccines.

PCR detection for syphilis diagnosis: Status and prospects.

Syphilis, a re-emerging public health problem worldwide caused by Treponema pallidum subsp pallidum (T. pallidum), usually induces systemic and chronic inflammation in hosts who do not receive timely therapy after exposing to high-risk factors such as leprous sexual contact. Before the treatment, rapid and accurate detection of syphilis is essential. However, the existing detection methods, which focus on the treponemal or non-treponemal antibody test, both have inherent limitations. For instance, both of them cannot distinguish the stage and severity of syphilis. Non-treponemal test such as RPR, which is generally deemed to be used for assessing treatment response, is influenced by biological false positives. Therefore, it is imperative to seek out a new and effective diagnostic test. With recent advancements in molecular biology and whole-genome sequencing, the molecular diagnosis has increased in popularity, especially the use of polymerase chain reaction (PCR). Here, we firstly present a mini-review on the research of PCR detection methods used for syphilis diagnosis over the past decade, and we then compare these methodologies to assess their potential and the challenges faced. This information can provide a fresh perspective to help researchers address the current challenges.

Data on the generation of rabbit infections and RPR titre changes in serum samples from syphilis patients at follow-up.

The data presented in this article are related to the research article entitled "Performance of novel infection phase-dependent antigens in syphilis serodiagnosis and treatment efficacy determination". The rabbit model [1], [2] is an appropriate animal model for studying syphilis, a classic sexually transmitted disease (STD). Live Treponema pallidum (T. pallidum, Tp) and inactivated T. pallidum were inoculated in the backs of New Zealand rabbits. RT-PCR was performed to determine whether T. pallidum DNA could be detected in different groups. Sixty paired serum samples from patients at follow-up were tested by RPR and recombinant Tp0971-, Tp0768-, Tp0462- and Tp92-based ELISA.

A rapid microwave synthesis of nitrogen-sulfur co-doped carbon nanodots as highly sensitive and selective fluorescence probes for ascorbic acid.

A ultrafast one-step microwave-assisted method was developed for the synthesis of nitrogen-sulfur co-doped carbon nanodots (N,S-CDs) by using ethylenediamine as the carbon source and sulfamic acid as the surface passivation reagent. The morphology and the properties of N,S-CDs were explored by a series of techniques, such as high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis absorption and fluorescence spectroscopy. The prepared N,S-CDs exhibit bright blue photoluminescence with a high fluorescence quantum yield (FLQY) up to 28%, and high stability and excellent water solubility. A N,S-CDs-based fluorescent probe was developed for sensitive detection ascorbic acid (AA) in the presence of Cu(2+), based on the mechanism that AA reduces Cu(2+) to Cu(+), then Cu(+) quenches the fluorescence of N,S-CDs through electron or energy transfer due to the interaction between Cu(+) and thiol ligand on the N,S-CDs surface. The observed linear response concentration range was from 0.057 to 4.0µM to AA with a detection limit as low as 18nM. The probe exhibited a highly selective response toward AA even in the presence of possible interfering substances, such as uric acid and citric acid. Moreover, these promising features made the sensing system used for the analysis of human serum and urine samples.